The primary goal of this Program Project Grant is to determine the effect of chronic heavy alcohol use on the systemic, CNS and PNS morbidity of HIV disease. Chronic heavy alcohol use may hasten systemic HIV disease progression (either via biological effects of via effects on treatment seeking and treatment adherence) resulting in increased CNS & PNS morbidity, or it may have direct effects on the CNS & PNS independent of systemic HIV disease progression. Both mechanisms and their effects will be evaluated in a two year longitudinal of HIV+ and HIV- chronic heavy drinkers and light/non drinkers. In support of these efforts, the core will serve five major functions. . The Core will provide the administrative oversight and support of the Program. . The Core will be responsible for screening and recruiting all subjects for the PPG, for scheduling and coordinating all subject assessments, for handing subject payments, for dealing with interactions with subjects' physicians and treatment facilities, and for tracking subjects and for calling them back for assessments at 6, 12, 18 and 24 months. . The Core will be responsible for virologic/immunologic assessments, assessment of the status of subjects' HIV disease and HIV disease treatment, drinking history, family density of drinking problems, nutritional status, risk behavior, treatment seeking behavior, treatment adherence, quality of life, and neuropsychological function. . The Core will be responsible for a CSF substudy comparing viral load and anti-viral drug levels in CSF versus blood. . The Core will be responsible for data management and design and coordination of statistical analyses across the PPG.